The influence of CT findings of bronchoalveolar lavage site on lavage results in smear negative pulmonary tuberculosis patients

SUN Mengyan; QIN lin; LI Chenghai; LYU Yan; WANG Yichuan; HE Wei; HOU Dailun

Abstract：Objective To investigate the effect of CT signs of bronchoalveolar lavage site on bronchoalveolar lavage fluid(BALF)smear,culture,and Xpert results in patients with smear negative pulmonary tuberculosis.Methods A retrospective analysis was conducted on the relationship between CT features of bronchoalveolar lavage site and BALF smear,culture,and Xpert results in 528 patients with smear negative pulmonary tuberculosis admitted to our hospital from.Results The positive rates of BALF smear,culture,and Xpert were 9.66%,32.39%,and 58.33%,respectively.Among them,the positive rates of BALF smear,culture,and Xpert in the lobe/segment of the lung where CT signs of bronchiectasis accompanied by thickening of the tube wall,bronchial stenosis,inflation bronchial sign,and drainage bronchial sign were higher than the negative rates,with statistical significance(P<0.05).There was a statistically significant difference in Xpert and culture positive and negative results obtained from BALF at the location of cavities,ground glass shadows,and tree bud signs(P<0.05).However,there was no statis-tically significant difference in the positive and negative rates of BALF results obtained from three types of CT signs:mass,simple bronchiectasis,and bronchial occlusion(P>0.05).Multivariate regression analysis showed that bronchiectasis accompa-nied by wall thickening,bronchial stenosis,and inflatable bronchogram were independent predictive factors for obtaining three positive lavage results(P<0.05).Conclusion Choosing the location of bronchial abnormalities,cavities,ground glass shad-ows,and tree bud signs for bronchoalveolar lavage in patients with smear negative pulmonary tuberculosis can improve the posi-tive rate of lavage results.